1. Field of the Invention
The present invention relates to a multi dust-collecting apparatus for a vacuum cleaner, and more particularly, to a multi dust-collecting apparatus that separates and collects dirt from air drawn in a vacuum cleaner by taking multi-steps.
2. Description of the Related Art
As is known, a dust-collecting apparatus for a conventional vacuum cleaner uses a dust-bag. However, the dust bag requires replacement when it becomes full and thus causes inconvenience and unpleasantness to a user. In an attempt to solve this problem, a cyclone dust-collecting apparatus separating dirt from drawn-in air by using centrifugal force has been suggested.
However, since there may occur backflow of dirt particles in the cyclone dust-collecting apparatus, a grill member or a filter is provided at an air discharge port for the purpose of increasing a dust-collection efficiency. An example of the cyclone dust-collecting apparatus is disclosed in the Korean Patent Laid-open No. 2002-0073464. However, because the grill member or the filter is provided at the air discharge port, a pressure loss is increased, which deteriorates a suction force. In order to maintain a suction force, a power of a suction motor has to be increased. However, this causes a high power consumption.
Currently developed multi cyclone dust-collecting apparatuses centrifugally separate dirt from drawn-in air by taking at least two steps. However, the multi cyclone dust-collecting apparatus has a lengthened passage and thus a suction force is lowered.